The capture of images for full depth (3D) viewing can be done with multiple coordinated imaging devices, and most frequently with just two. Presently, and for the most part, these images are stored, manipulated and then re-created as multiple images for viewing on flat screens. To see the images in full-depth, observers using prior art systems typically wear switching, polarized or anaglyph glasses. With varying degrees of success this has been done for many years. What has been done with much more difficulty is to re-create the images without the use of viewing glasses, and more difficult still to do this without converting from capture to display format in milliseconds, that is, in real time.
Within the field of directly viewing full-depth 3D images without viewing glasses (auto-stereoscopy), a number of techniques have been used to re-create full-depth images from flat screens. The most successful of these has been lenticular arrays, in which each cylindrical lens creates multiple points of view by bending the light from several LEDs, giving, in aggregate, an observer a vivid sense of depth. This is especially true at “sweet spots”, where a confluence of beams arrive in close coincidence.
A different technique physically divides the light from the emitting elements into left and right with small strips, so that each eye sees just one half of the full perspective. These are called “parallax barriers”. They have long been used, but are generally limited to just two points of view. Efforts to make them work well include liquid crystals, active barriers, reversed barriers and multiple barriers.
Another approach is a rear projection system with multiple points of view, possibly hundreds. This replicates the way we see scenes with our eyes, acquiring a great number of image snapshots from different perspectives to create full depth panoramas in our visual cortex. This approach requires as many cameras and as many projectors as there are points of view to recreate. These cameras and projectors must all be carefully coordinated both in capture and display. Even small failures, such as those of intensity or color balance, in any camera or projector will leave streaks in the display. For so many imaging devices storage requires considerable memory and streaming substantial bandwidth. Nonetheless multiple projectors can produce full-depth and full-parallax images of great quality.
Another technique using MEMS structures, utilizes tiny flipping solid-state mirrors to guide light through narrow-angle screens to create images of differing viewpoints.